Cambridge, MA - In our solar system, only one planet is blessed with an ocean: Earth. Our home world is a rare, blue jewel compared to the deserts of Mercury, Venus and Mars. But what if our Sun had not one but two habitable ocean worlds?

Astronomers have found such a planetary system orbiting the star Kepler-62. This five-planet system has two worlds in the habitable zone - the distance from their star at which they receive enough light and warmth for liquid water to theoretically exist on their surfaces. Modeling by researchers at the Harvard-Smithsonian Center for Astrophysics (CfA) suggests that both planets are water worlds, their surfaces completely covered by a global ocean with no land in sight.

"These planets are unlike anything in our solar system. They have endless oceans," said lead author Lisa Kaltenegger of the Max Planck Institute for Astronomy and the CfA.

An international team of scientists analyzing data from NASA's Kepler mission, which includes Lisa Kaltenegger from the Max Planck Institute for Astronomy, has announced the discovery of the first small, potentially rocky Kepler planets, orbiting in the Habitable Zone of their star.

The planets, called Kepler-62e and Kepler-62f, orbit a star that is slightly smaller and cooler than our own Sun. Going by their radii, these planets should be rocky, making them our best candidates for habitable planets out there yet. Analysis by Dr. Kaltenegger indicates that both planets lie in their host star's habitable zone – where liquid water is possible, the necessary precondition for life as we know it.

We're a step closer to knowing if our galaxy is home to a multitude of planets like Earth or if we are a rarity. The three habitable zone super-Earth-size planets are in two systems containing a total of seven newly discovered planets:

NASA's Kepler mission has discovered two new planetary systems that include three super-Earth-size planets in the "habitable zone," the range of distance from a star where the surface temperature of an orbiting planet might be suitable for liquid water.